Add ability to record uncertainties along with each prediction

[ardunn]

No description provided.

[ml-evs]

Just to carry on the discussion here:

Do you think it should be a 95% conf interval with assumed normal distribution? So like for each sample you would get [prediction, lower bound, higher bound] or something

Originally posted by @ardunn in #39 (comment)

This works for us!

It probably shouldn't be included in the metadata for now just because that will be a lot of data to be shown on the MODNet algorithm page for the website.

Originally posted by @ardunn in #39 (comment)

Maybe a more general way of providing per-prediction data/metadata (that doesn't clog up the web page) could be useful too, though beyond the scope of this issue.

[ardunn]

@ml-evs That actually sounds like a better idea, just having a metadata field for each prediction rather than having an array or something. So for each prediction it would look like:

{"mb-XXXX": 
    {
        "prediction": 8.94
        "metadata": {
            { <whatever metadata goes here, e.g. uncertainties>}
    }
}

[ardunn]

no longer needed, made the prediction field unnecessarily complex. arbitrary metadata can be kept per fold in params and as of #58 it will no longer spam the webpage if very large.